Question

i successfully added a contextmenu to my webbrowser with this javascript code:

public void AttachContextMenu()
        {
            try
            {
                if ((App.Current as App).Browser.IsScriptEnabled)
                {
                    (App.Current as App).Browser.InvokeScript("execScript", "function FindParentLink(item) \r\n{\r\n\tif (!item.parentNode)\r\n\t\treturn null;\r\n\tif (item.tagName.toLowerCase() == 'a') \r\n\t{\r\n\t\treturn item;\r\n\t} \r\n\telse \r\n\t{\r\n\t\treturn FindParentLink(item.parentNode);\r\n\t}\r\n}\r\n\r\nfunction FindParentImage(item) \r\n{\r\n\tif (!item.parentNode)\r\n\t\treturn null;\r\n\tif (item.tagName.toLowerCase() == 'img') \r\n\t{\r\n\t\treturn item;\r\n\t} \r\n\telse \r\n\t{\r\n\t\treturn FindParentImage(item.parentNode);\r\n\t}\r\n}\r\n\r\nfunction HandleContextMenu() \r\n{\r\n\tvar linkItem = FindParentLink(event.srcElement);\r\n    var imageItem = FindParentImage(event.srcElement);\r\n    var notifyOutput = '';\r\n    if (linkItem != null) if (linkItem.href != null) notifyOutput += linkItem.href;\r\n    if (imageItem != null) if (imageItem.src != null) notifyOutput += imageItem.src;\r\n    if (notifyOutput != '')\r\n        window.external.notify(notifyOutput);\r\n    else\r\n\t\twindow.external.notify('NOTLINKIMG');\r\n}");
                    (App.Current as App).Browser.InvokeScript("execScript", "document.oncontextmenu = HandleContextMenu;");
                }
            }
            catch
            {
            }
        }

this method is used everytime the browser navigated.
So, the scriptnotify code, which will be used when the user holds a link :

 if (e.Value.ToString() != null && IsValidUri(e.Value.ToString()))
            {
                ContextMenu cm = new ContextMenu();
                MenuItem menuItem0 = new MenuItem() { Header = "X", Tag = e.Value };
                menuItem0.Click += new RoutedEventHandler(X_Click);
                MenuItem menuItem1 = new MenuItem() { Header = "Y", Tag = e.Value };
                menuItem1.Click += new RoutedEventHandler(Y_Click);
                MenuItem menuItem2 = new MenuItem() { Header = "Z", Tag = e.Value };
                menuItem2.Click += new RoutedEventHandler(Z_Click);

                    cm.Items.Add(menuItem0);
                    cm.Items.Add(menuItem1);
                    cm.Items.Add(menuItem2);


                ContextMenuService.SetContextMenu(Browser, cm);
                cm.IsZoomEnabled = false;
                cm.VerticalOffset = mouseClickPosition.Y;
                cm.IsOpen = true;
            }

so far, i hope i made everything right.
now, it randomly works. nearly 50% of tries cause a error, Visual studio navigates to a blue-white frame named “No source available” and throws a NullReferenceException.

Where should this be solved? already set a try-catch block around the hole 2 method, no change :/

hope you have some ideas

greets
roqstr

Answer 1

don’t got it working, but there’s a workaround:

AttachContextMenu()

-> holding a link will push the url to the scriptnotify method.

build a custom contextmenu & everything is fine.